Boston — Months before the lurid case of a Miami man who allegedly cannibalized a homeless man's face, police and emergency officials as far flung as Maine and Louisiana were coping with their own surreal 911 calls also linked to the drug quaintly known as "bath salts":

A 21-year-old Louisiana man who cut his own throat then shot and killed himself after being treated by doctors. A Maine man who got off his motorcycle in the middle of a highway and started trying to hit passing cars with a piece of wood. A Maine woman who thought her teeth were filled with ticks and tried to cut them out with a knife.

The common theme is a strong suspicion that the causes of such erratic behavior were the cheap, potent, innocent-looking, and, until recently, legal and undetectable, synthetic drugs that spark hallucinatory, paranoid rages.

Bath salts are the latest narcotics trend to rattle communities mainly in the eastern US, baffling emergency-room doctors, spooking police officers, and prompting lawmakers to rush through bans and emergency legislation. With echoes of earlier drug epidemics – crack cocaine in the 1980s, prescription-drug abuse in 1990s, crystal meth in the 2000 – the bath-salt scare is both shocking and routine.

"It’s nothing new. It’s stimulant abuse in its most recent formulation, and unfortunately, it leads to bad consequences, but it’s really no different than other waves of other stimulant abuses in the past,” says Tamas Peredy, an emergency-room physician in Portland, Maine, and medical director of the Northern New England Poison Center.

A Miami police official has speculated that bath salts were behind the bizarre May 26 incident in which a 31-year-old man allegedly tore off the clothes of a homeless man under a highway and ripped off parts of his face. Toxicology reports have not been released on the attacker, who had to be shot at least five times by police trying to stop the assault, according to The Miami Herald.

Unlike cocaine or heroin, bath salts are synthetic stimulants that contain various chemical compounds. Emergency rooms and poison centers report that overdoses have caused problems ranging from paranoia to hallucinations. It is unclear how addictive the bath salts are.

“We had people telling us: ‘This is the worst thing I ever did, but the cravings were so intense that I used it for eight days straight,’ ” says Louisiana Poison Center Director Mark Ryan, who in 2010 was one of the first doctors to document the surge in cases.

Until recent months, the drug was legal in most states, widely available in tobacco shops or convenience stores, sold under other names like Ivory Wave or Vanilla Sky and coming in various shapes and forms. When it was still legal, a person could buy for $20 to $40 a small Ziploc bag or matchbox-sized container with powder or crystals that “smells like old feet,” Dr. Ryan says, and get a high that would otherwise cost, for example, $2,000 worth of cocaine.

“The packaging would say something like ‘DEA Compliant’ or ‘Not for Human Consumption. If Consumed Call the Poison Control Center,’ ” he says. “It was almost like the manufacturer was thumbing their nose at us.”

Still, bath salts can easily be found on the Internet, merely by changing search terms. The fact that they are distributed via mail and the Internet rather than by old-fashioned drug couriers helps explain why more rural places such as Maine were at the cutting edge of the epidemic rather than big cities, says Chief Deputy Troy Morton from the Penobscot Country Sheriff’s Deptartment in Maine, which was the hardest hit county in that state.

“People thought: ‘How bad could it be? It’s called bath salts,’ ” Mr. Morton says. “Once it got here and people learned about it, it took off like fire because it was legal, and it was extremely cheap.”

By some accounts, the wave of abuse may have already passed. The number of bath salt-related reports made so far this year by the country’s 57 poison control centers stands at 1,007 as of May 1, according to the American Association of Poison Control Centers. In all of 2011, 6,138 calls were reported. Louisiana and Maine show a similar drop in figures.

Most professionals, however, believe those numbers severely undercount the prevalence of bath salts’ use, as police or hospital doctors gain a better understanding of how to deal with overdose cases. Most also believe that the drop is due not necessarily to declining use, but to users understanding how to take the drugs and get the euphoric or hallucinatory effects without the psychotic episodes.

In Maine, Morton says, what tipped the balance was an aggressive education campaign: “We haven’t stopped it, it’s still here. It’s just not like it was: people being out on the lawn, naked and shadowboxing.”